"It was established that in 2011, when he served at the Russian Interior Ministry, E.A. Chistov established contact with US Central Intelligence Agency, acting on his own initiative and out of self interest," the FSB said in a statement.

The FSB said Chistov admitted to passing state secrets to the CIA in exchange for money.

"He was recruited by the CIA and fulfilled its tasks, collecting and handing over information classified as state secrets for three years in exchange for material reward," the FSB said.

Since the Ukraine crisis last year, several people have been convicted on espionage related charges in Russia.

Last month, a man was sentenced to 12 years in prison for passing secrets to Ukraine. In September,